public virtual string Alter(Alter alter, SqlOptions sql)
{
var statement = $"ALTER TABLE {sql.IdentifieName(alter.Table)} ";
switch (alter.WhatToModify)
{
case WhatToAlter.PrimaryKey:
var columnPK = sql.IdentifieName(alter.Column);
foreach (var c in alter.ExtraPrimaryKeyColumns)
{
columnPK += $",{sql.IdentifieName(c)}";
}
statement += alter.AlterType == AlterType.Add
? $"ADD CONSTRAINT {sql.SafeIdentifieName(alter.ConstraintName)} PRIMARY KEY ({columnPK})"
: "DROP PRIMARY KEY";
break;
case WhatToAlter.ForeignKey:
statement += alter.AlterType == AlterType.Add
? $"ADD CONSTRAINT {sql.SafeIdentifieName(alter.ConstraintName)} FOREIGN KEY ({alter.Column}) REFERENCES " +
$"{sql.IdentifieName(alter.ReferencesTable)}({sql.IdentifieName(alter.ReferencesColumn)})"
: $"DROP FOREIGN KEY {sql.SafeIdentifieName(alter.ConstraintName)}";
break;
case WhatToAlter.Unique:
statement += alter.AlterType == AlterType.Add
? $"ADD CONSTRAINT {sql.SafeIdentifieName(alter.ConstraintName)} UNIQUE ({alter.Column})"
: "DROP INDEX KEY";
break;
case WhatToAlter.Column:
switch (alter.AlterType)
{
case AlterType.Add:
statement += $"ADD {alter.NewColumnToAdd.ToString(sql)}";
break;
case AlterType.Drop:
statement += $"DROP COLUMN {sql.IdentifieName(alter.Column)}";
break;
case AlterType.Alter:
statement += $"MODIFY COLUMN {sql.IdentifieName(alter.Column)} " +
$"{sql.CSharpTypeToSqlDataType(alter.DataTypeToAlter, alter.DataTypeSizeToAlter, alter.DataTypeDigitsToAlter)}";
break;
}
break;
}
return(statement);
}
